Offense has been booming for the Yankees to start 2017. That is, for most of the Yankees, at least. While Aaron Judge and Chase Headley, amongst others, have fired on all cylinders to begin the year, Brett Gardner has not. The Yankees’ leadoff hitter has sputtered at the plate, but fortunately hasn’t held back the lineup from churning out runs at a high rate. It’s early, so Gardner has time to catch up to his teammates, but it’s disconcerting to see the left fielder struggle as he gets older and declines.

In 66 plate appearances, Gardner is hitting a paltry .182/.318/.236 with no home runs and five stolen bases (68 wRC+). He’s walked more than a fair share (16.7%), but is also going down on strikes quite often (24.2%). Yes, it’s still early enough in the season for Gardner to turn it around, but it’s also fair to start considering the following questions: Is he healthy? Should he be moved out of the leadoff spot? Should he cede some playing time to Aaron Hicks and Jacoby Ellsbury? Is this just a slump, or something more?

The only way to properly address those questions is to determine whether or not Gardner’s poor offensive performance is “real”. Yet, it’s problematic to make such an assessment in the early stages of a season. Players go through slumps all the time at various points of any given season. Sometimes, they’re not as noticeable when they’re in July. Other times, and perhaps in this case, slumps are far more glaring because they represent the year to date stat line.

Looking closer, Gardner's first 35 plate appearances weren't so bad. They were rather Brett Gardner-esque, actually. A .258/.343/.323 (94 wRC+) is more or less the output that many expected from him prior to the season. It was rather ho hum until his 35th trip to the dish on April 12th:

Since that collision, Gardner's line is .083/.290/.125 in 31 plate appearances. Perhaps it's a coincidence that the left fielder has been mired in a rut thereafter. Or, maybe he's still feeling the lingering effects. Maybe I'm looking too far into 31 plate appearances! That's very possible, with small sample sizes and all. That said, it feels like a convenient and reasonable explanation for Gardner's struggles. Perhaps with truth serum, Gardner would concede as much. That being said, I'm concerned there's more to this than heath. It may be a contributing factor, but there were reasons to be concerned about the 33 year-old even before this slump began (and this season, for that matter).

There are signs of decline existent throughout his offensive game that have come to life in the past year or two. In particular, the pop that emerged in 2014, when he hit a career high 17 home runs, has dissipated. That year, Gardner posted a .166 isolated power which has declined steadily thereafter: .140 in 2015, .101 in 2016, and .055 this year. With that in mind, it’s no surprise that various measurements of contact quality are trending downward too. According to Fangraphs, Gardner’s percentage of Hard Contact is 20.5% this season, below his 23.1% career mark. That’s down from 25.8% last season, and further below the 28.9% mark he set during his 2014 power surge. The statcast data, available on Baseball Savant and dating back to 2015, follows suit:

Source: Baseball Savant

On every type of batted ball, his average exit velocity has decreased since 2015. Overall, Gardner's average exit velocity has decreased from 88.8 MPH in 2015, to 86.9 MPH in 2016, to 81.6 MPH in 2017. That’s not good. It’s no wonder that Gardner’s power is down and that his BABIP currently stands at .256 (career .317). He’s not striking the ball well whatsoever.

I do want to caution reading too much into the Statcast data for 2017 given the small sample of batted balls (38 in 2017), however, I don’t think it would be shocking to see the average exit velocities down across the board for Gardner by the end of the season. It was down in 2016 vs. 2015, and the hard contact data on Fangraphs makes it evident that there’s been a negative trend for a few years now.

Gardner’s approach at the plate is out of whack, too. He’s been very passive in the early goings of 2017, swinging at only 29.9% of pitches compared to 35.9% for his career. The positive in this is that he’s only chasing 19.5% of pitches out of the strike zone (compared to 20.7% career), which helps explain his high walk rate. However, he’s laying off an exorbitant amount of pitches in the zone: 42.4% Z-swing vs. 49.4% career. Gardner’s always been a patient hitter, but even that is out of the norm for him.

Source: Fangraphs

It seems that opponents have caught on and are challenging Gardner more frequently. Thus far, opposing pitchers have thrown fastballs to Gardner 68.3% of the time, up from 62.2% in 2016 and 62.8% in 2015. Maybe that is a small sample size issue, but it could also point to opponent’s lack of fear of Gardner doing damage. Further, it might be a sign that Gardner's bat speed has decreased. Circling back to the collision a couple weeks ago could explain the lack of a full strength swing and/or confidence in using maximum effort. So from a pitcher's standpoint: given that there hasn’t been much pop in Gardner's bat and he’s been overly patient at the plate, why not challenge him with heat?

At 33 years old, Gardner is no spring chicken. Decline is to be expected at this stage of one’s career, so it’s not surprising that he isn’t the same player he was in 2014. That also doesn’t mean that he’s a true 68 wRC+ type of hitter in 2017, which is what he’s provided thus far. ZiPS and Steamer have rest of season projections available on Fangraphs’ player pages, and the two systems forecast 94 and 97 wRC+ respectively for Gardner the rest of the way. That’s right in line with who he was a year ago. And given his solid defense and baserunning, such a performance would still be valuable as a regular player going forward this season. That said, time is ticking and the Yankees can’t wait forever for Gardner to snap out of it, especially considering how his peers are hitting.

Hicks and Ellsbury, the two teammates that Gardner is at most risk to losing time to, are performing well thus far in 2017. Hicks might be in the midst of a breakout, posting a 224 wRC+ in 44 plate appearances this month. Small sample size, I know. However, he closed last season positively (105 wRC+ in 129 plate appearances) and is still only 27 years old. As a former first rounder and top prospect, the idea of him suddenly hitting his stride is a distinct possibility. For Ellsbury, his 141 wRC+ in 71 trips to the plate this year has a bit of helium to it, particularly because he’s a 33 year-old who tends to get banged up and wear down over a long season.

For what it’s worth, Gardner’s projections are in line or better than the anticipated output for both Hicks and Ellsbury. Despite the latter two’s hot starts, the needle hasn’t moved much for their projected output for the rest of the season. ZiPS and Steamer agree on a 91 wRC+ for Ellsbury the rest of the way. There’s some discord on Hicks, who projects for a 90 wRC+ according to ZiPS while Steamer expects a 100 wRC+. Like I mentioned before, though, the Yankees won’t fall back on projections if Gardner continues to be punchless if Hicks and Ellsbury continue hit. Let's not forget Clint Frazier or Dustin Fowler in Triple-A either, who could force a promotion. With Gardner, how long the Yankees rest on their laurels is up for debate.

It's April 25th, so writing off Gardner would be silly to do. Maybe it really is the collision that's still hampering him, and once he fully recovers, he'll revert back to the player we expected preseason. Who knows? What we do know is that there are a few legitimate reasons to be concerned. He's older. His power is down. His quality of contact is down. He's being passive. None of those are good things to exhibit over extended periods of time, which Gardner has done. Again, he's still capable of being a solid regular this season, but he does have others breathing down his neck for more opportunities.